The General Electric GAU-8/A Avenger is a 30 mm, hydraulically-driven seven-barrel Gatling-type rotary cannon that is mounted on the United States Air Force's A-10 Thunderbolt II. It is among the largest, heaviest and most powerful aircraft cannons in the United States military. Designed specifically for the anti-tank role, the Avenger delivers very powerful rounds at a high rate of fire.